48 A CONTRIBUTION TO THE KNOWLEDGE OF 



and thus has the appearance of being anterior to the pygidium. No pores 

 or ducts of any sort are apparent either dorsally or ventrally. 



In the very late second stage the derm becomes heavily chitinized 

 and suffused with a black pigment. Apparently the derm dehisces around 

 the posterior margin of the pygidium to permit the escape of the larvae. 

 At an earlier period (Fig. 22F) the derm is membranous except for the 

 pygidium, which is similar in form to the usual Diaspine type but entirely 

 without lobes or plates (Fig. 22B), pointed and with the tip slightly 

 emarginate. Anal ring borne about the center of the dorsal side of the 

 pygidium. On both dorsal and ventral sides there are a number of small 

 points which may be either pores or the points of insertion of small spines. 



First stage. Derm heavily chitinized at the end of this period. 

 Early first stage resembling that of other Diaspinae, but without lobes at 

 the posterior end of the body (Fig. 22C). Antennae (Fig. 22E) six- 

 segmented, last segment not annulate. 



Protodiaspis edentata n. sp. 

 Fig. 23. 



Type host and locality. From Acacia greggii, near Vail, Ariz. 

 Habit. In all respects resembling the preceding. Male not ob- 

 served. 



Fig. 23. Protodiaspis edentata n. sp. : pygidium of adult female. 



Morphological characteristics. Adult female with the pygidium 

 quite smoothly rounded, bearing four small spines along its margin. On 

 the dorsal side the anterior portion appears to be somewhat elevated 

 above the remainder and separated from the remainder by a curving line. 

 Anterior to this line the derm is rather weakly chitinized. On the ven- 

 tral side the pygidium appears not to be sharply separated from the 

 abdomen. 



